Fractals Make Better Superconductors

Aug 16, 2010By: Story content courtesy of the London Centre for Nanotechnology, UK

European research team discovered that optimal superconductivity was obtained when the microstructure was most ‘connected’

Researchers from Rome, Grenoble and London report that the strength of the superconductivity – its ability to persist as temperature is increased– correlates in certain oxide materials with structures visible over a range of length scales. Until now, scientists have focused on structure at the nanometer (0.0000001 millimeters) – the distance between neighboring atoms - scale as the determinant of the unusually strong superconductivity of the oxides of copper. For the team’s published scientific article, the researchers describe how they used a new technique of X-ray microscopy to examine a copper oxide superconductor whose internal structure could be changed via simple heat treatments.

Ideal superconductivity occurred when the microstructure was most ‘connected,’ meaning that it is possible to trace a path with the same nanostructure (exhibited by oxygen atoms) over a large distance. The microstructure in this case was ‘fractal’: if one were to zoom in on the material’s structure at increasing levels of magnification, its appearance would remain the same.